feat(booth): asks — a multiple-choice question a session poses in a booth, answered by the operator as a radio form + notes, written back as an answer sidecar

- booth/asks.py (stdlib): <stem>.ask.json question / <stem>.answer.json answer; normalise+validate, atomic write, list with answer folded in, broken asks surfaced not hidden
- POST /b/<name>/answer: validates choice against the ask (400), unknown stem 404, re-answer overwrites
- booth.html asks panel above the gallery; amber open / green answered; JS-off form POST; index card + booth header badge for open asks
- CLI: booth ask / asks / answer [--wait [SECS]]; remote sessions poll <stem>.answer.json over HTTP
- ask/answer files excluded from gallery items and item counts; 23 tests; v0.1.9

booth/app.py

@@ -75,6 +75,16 @@ KEEP_MARKER = ".forever"
 # The link-board logic lives in booth/links.py (stdlib only) so the `booth` CLI
 # can use it without pulling FastAPI in. Re-exported here because call sites and
 # tests already reference these names through app.
+from booth.asks import (  # noqa: E402
+    ANSWER_SUFFIX,
+    ASK_SUFFIX,
+    AskError,
+    is_answer_file,
+    is_ask_file,
+    list_asks,
+    valid_stem,
+    write_answer,
+)
 from booth.links import (  # noqa: E402
     LINK_LOCK,
     LINKS_FILE,
@@ -215,7 +225,14 @@ def list_booths(data_dir: Path, ttl_seconds: float, now: float | None = None) ->
     for child in data_dir.iterdir():
         if not child.is_dir() or child.name.startswith("."):
             continue
-        files = [p for p in child.rglob("*") if p.is_file() and not p.name.startswith(".")]
+        files = [
+            p for p in child.rglob("*")
+            if p.is_file() and not p.name.startswith(".")
+            and not is_ask_file(p.name) and not is_answer_file(p.name)
+        ]
+        # Asks are questions, not items: counted separately so the index can
+        # flag a booth that is waiting on the operator.
+        asks = list_asks(child)
         kinds = {"image": 0, "video": 0, "audio": 0, "other": 0}
         thumb_url = None
         for f in files:
@@ -234,6 +251,8 @@ def list_booths(data_dir: Path, ttl_seconds: float, now: float | None = None) ->
                 "has_index": (child / "index.html").is_file(),
                 "uploaded": (child / UPLOAD_MARKER).exists(),
                 "kept": is_kept(child),
+                "asks_total": len(asks),
+                "asks_open": sum(1 for a in asks if a["answer"] is None and not a["error"]),
                 "expires_in": max(0.0, ttl_seconds - (now - mtime)),
                 "mtime": mtime,
             }
@@ -249,7 +268,12 @@ def build_gallery(child: Path) -> list[dict]:
     next to `a.png`) is consumed as that item's caption rather than shown itself —
     the natural way to label an A/B pair.
     """
-    all_files = [p for p in child.rglob("*") if p.is_file() and not p.name.startswith(".")]
+    all_files = [
+        p for p in child.rglob("*")
+        if p.is_file() and not p.name.startswith(".")
+        # `*.ask.json` / `*.answer.json` render as the asks panel, not as tiles
+        and not is_ask_file(p.name) and not is_answer_file(p.name)
+    ]
     by_rel = {p.relative_to(child).as_posix(): p for p in all_files}
     caption: dict[str, str] = {}
     sidecars: set[str] = set()
@@ -620,11 +644,32 @@ def create_app(
                     )
                     if (booth / LINKS_FILE).is_file() else []
                 ),
+                # Asks: multiple-choice questions a session left for the
+                # operator, rendered as forms above the gallery (open ones)
+                # or as their recorded answer. See booth/asks.py.
+                "asks": list_asks(booth),
                 "uploaded": (booth / UPLOAD_MARKER).exists(),
                 "expires_in": max(0.0, ttl_seconds - booth_age_seconds(booth)),
             },
         )
 
+    @app.post("/b/{name}/answer")
+    def booth_answer(request: Request, name: str, ask: str = Form(...), choice: str = Form(...),
+                     notes: str = Form("")):
+        """Record the operator's answer to one ask: validates the choice
+        against the ask's options and writes `<stem>.answer.json` atomically.
+        Re-submitting overwrites — the sidecar is the current answer. 404 for
+        an unknown/invalid stem, 400 for a choice the ask does not offer."""
+        booth = resolve_booth(name)
+        if not valid_stem(ask) or not (booth / f"{ask}{ASK_SUFFIX}").is_file():
+            raise HTTPException(status_code=404, detail="no such ask")
+        who = request.client.host if request.client else ""
+        try:
+            write_answer(booth, ask, choice, notes, who=who)
+        except AskError as exc:
+            raise HTTPException(status_code=400, detail=str(exc))
+        return RedirectResponse(url=f"/b/{quote(name, safe='')}/#ask-{quote(ask, safe='')}", status_code=303)
+
     @app.get("/b/{name}/view", response_class=HTMLResponse)
     def booth_view_file(request: Request, name: str, f: str):
         booth = resolve_booth(name)